Sticking to a regular exercise program is tough enough when you're healthy. But what if you’re in pain, are too weak to get out of bed or are having trouble breathing? Chronic illnesses like arthritis, fibromyalgia and others make it even more challenging. Here are doctor-recommended tips for conquering condition-related obstacles...

Achey joints, wheezing and fatigue are a convenient excuse to skip exercise. After all, fear that a workout might make you feel worse and leave you in pain is reasonable.

But the right dose of exercise can be a prescription for relief. Under a doctor’s care, working out has been proven to alleviate symptoms and reduce the risk of complications for some disorders, such as arthritis, diabetes and fibromyalgia.

"The body has a 'use it or lose it' mentality," says Jacob Teitelbaum, M.D., medical director of the Fibromyalgia and Fatigue Centers of America. "So the loss of fitness that occurs from lack of exercise can be more crippling than the illness itself."

Read on for top doctors’ tips to help you exercise – no matter what ails you.

"Over time, [inactivity] leads to a decrease in strength, range of motion and overall activity, which in turn causes movement to get even more painful," Dr. Teitelbaum says.

In fact, it’s possible to delay the onset of osteoarthritis, a degenerative joint disease, by doing low-impact sports, such as walking or swimming, according to a 2010 University of California, San Francisco study.

Exercise Rx: Do a combination of water- and land-based exercise to improve mobility.

"Aquatic exercise in warm water takes the load off joints, easing pain," says Erin DiCapo, a physical therapist at theRehabilitation Institute of Chicago.

But also include land exercise in your workout regimen, because women’s bones need to bear loads to stay strong. Walking, tai chi and yoga are good, joint-friendly, skeleton-strengthening exercise choices, according to the National Osteoporosis Foundation.

Another tip: Schedule workouts away from peak pain times. For example, if you experience stiff joints in the morning – a common arthritis symptom – exercise later in the day.

Watch out! “Doing too much too soon may make you feel as if you've been hit by a truck the next day,” Dr. Teitelbaum says. "Rest a few days and try again at a lower intensity."

3. Obesity Overweight and obese women have additional incentive to get off the couch: Exercise improves weight loss by raising the sensitivity of neurons that govern fullness, according to a 2010 Brazilian study from the University of Campinas.

But one of the biggest hurdles to exercise for overweight women is overcoming a negative self-image.

"They don’t experience the release of endorphins [feel-good brain chemicals] because they become tired too quickly and give up faster,” Dr. Fruge says.

Exercise Rx: Replace negative, critical statements with positive reinforcement, advises Dr. Fruge. For example, instead of I hate exercise, think, It's important that I just move more each day. Each time, I get leaner and more fit.

Joining a support group may also improve the likelihood of success.

That increases the chances of maintaining an active lifestyle, Dr. Fruge says.

For example, join a women's walking group or grab a friend and go on a hike.

“Most importantly, be active five to seven times a week," she says. Twenty minutes of daily activity follows the American College of Sports Medicine recommendation of 150 minutes of moderate aerobic activity.

Watch out! If you become short of breath, have chest pain and feel dizzy during exercise, see a doctor immediately.

4. DiabetesResearch has proven that exercise is a crucial part of diabetes management.

In fact, a combination of aerobics and resistance training lowered blood-sugar levels in people with type 2 diabetes, according to a 2011 study published in the New England Journal of Medicine.

Workouts increase insulin sensitivity (the ability of cells to take up insulin, thereby reducing blood glucose) and weight management.

But balancing food, activity and glucose-lowering medication is tricky because of the risk of low blood sugar, says Francine R. Kaufman, M.D., chief medical officer and vice president at the University of Southern California and a past president of the American Diabetes Association.

Exercise Rx: Whatever your current activity level, increase it gradually, Dr. Kaufman advises. “A person with diabetes needs to learn the impact of exercise on their glucose levels and may need to adjust their therapy accordingly.”

“You also must take in additional carbohydrates before exercise to avoid hypoglycemia,” she says.

Watch out! Diabetics are at risk forhypoglycemia, which can be triggered by exercising because exercise acts like insulin to lower blood sugar levels, says Dr. Kaufman. Symptoms include cold sweats, confusion, fatigue, convulsions and blurry vision.

“Hypoglycemia can occur anytime during exercise, as well as later that night,” she says.

If symptoms occur, check blood-sugar levels. If they’re below 70 mg/dL, take a tablespoon of honey, 1/2 cup of regular (not diet) soft drink or fruit juice, or a serving of glucose gel to bring up levels.

But it can also trigger "symptoms of wheezing, a feeling of tightness in the chest and shortness of breath," saysMarjorie Slankard, M.D., clinical professor of medicine at Columbia University College of Physicians & Surgeons and director of the Allergy Clinic at Columbia Doctors Eastside.

Do stop-and-go exercises, including sports like tennis or swimming, which trigger fewer asthma symptoms than running and other long-endurance exercises.

You may also want to use a bronchodilator 15 minutes before working out to open airways and ease or prevent symptoms, Dr. Slankard says. Effects of short-acting bronchodilators typically last up to four hours. Longer-acting beta-agonist inhalers can help for up to 12 hours.

Watch out!Don't push beyond your capability, Dr. Slankard says. "Otherwise, symptoms can escalate to the point where you can pass out – or worse."

That means you could become hypoxic (when the body becomes deprived of oxygen) and suffer an abnormal heart rhythm. Or, if you lose consciousness and pass out, you could fall and suffer a brain injury.

If you have frequent asthma attacks during or after exercise, ask your doctor to reevaluate medications.

7. Allergies
Exercising outdoors during high pollen-count days can trigger symptoms for several days after your workout, Dr. Slankard says.

Also, take a non-drowsy antihistamine the night before to prevent a flare-up, she says.

For severe allergies, a prescription nose spray may keep your nose clear while you’re running, Dr. Slankard says. But “some people become decongested from the adrenaline produced while running."

Once home, shower and wash your hair to get rid of pollen.

Watch out! If symptoms become progressively worse, see a doctor for preventive medication.

What’s Your Fitness Style?Aspects of your personality determine the kind of exerciser you are, so if you're in a fitness rut, it's time to put your unique interests back into the workout equation. Take this quiz to find out what types of exercise are right for you.

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